1. Field of the Invention
The present invention relates to test circuits, and particularly to a voltage test circuit for testing a computer power supply.
2. Description of Related Art
A computer power supply is typically designed to convert 110V-240V AC from the mains, to several low-voltage DC outputs for internal components of the computer. The most common computer power supplies are built to conform to the ATX form factor. Before selling, manufacturers need to perform tests on the computer power supplies, such as output ripple test, noise test, compatibility test for capacitive load, and so on.
A conventional voltage test circuit for testing a computer power supply includes a plurality of connectors, filter capacitors, and electrical loads. The connectors are configured for simulating power interfaces of a motherboard. Connectors of the computer power supply are plugged into the corresponding connectors of the voltage test circuit, and nodes between the connectors of the computer power supply and the corresponding connectors of the voltage test circuit are grounded via the filter capacitors, and connected to the electrical loads. When voltages of the computer power supply are tested, each of the nodes between the connectors of the computer power supply and the corresponding connectors of the voltage test circuit is also connected to an oscilloscope via a lead to inspect output ripple and noise level of the voltages of the computer power supply. And then some capacitive loads and the electrical loads are connected to the connectors of the computer power supply. The compatibility level of the computer power supply can be determined by examining indicators of the electrical loads. However, with the ever increasing speeds of computers, standards of the computer power supply are more complicated than before, and the connectors of the conventional test circuit can not satisfy that trend. Further, the oscilloscope is connected to the computer power supply via a probe of the oscilloscope, the probe often does not make good enough contact with the nodes between the connectors of the computer power supply and the corresponding connectors of the voltage test circuit, and so the test results may not be accurate. Moreover, the capacitive loads need to be soldered onto the voltage test circuit every time, which wastes time and is very inconvenient.
What is desired, therefore, is to provide a voltage test circuit which overcomes the above problems.